Comparison of evoked electromyography in three muscles of the hand during recovery from non-depolarising neuromuscular blockade

The evoked electromyographic responses to supramaximal train of four stimulation of three muscles, all innervated by the ulnar nerve, were compared during recovery from non-depolarising neuromuscular blockade. The abductor digiti minimi was the most resistant to neuromuscular blockade (P <0.001) and the most repeatable (repeatability coefficient 4.4%) when compared with the adductor pollicis (5.9%) and the first dorsal interosseous (5.8%). The abductor digiti minimi had a bias of 0.1 compared to the adductor pollicis and first dorsal interosseous and its limits of agreement were more acceptable (-0.10 to 0.30) at a train of four ratio of 0.9. The electromyography train of four of the adductor pollicis and first dorsal interosseous at 0.8 is equivalent to an electromyography train of four of 0.9 at abductor digiti minimi.